This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. BNP levels have shown to be elevated in patients adult patients with head injury or subarachnoid hemorrhage, as shown in small pilot studies. This protocol will look at BNP levels at pediatric head trauma patients that come to CHLA for Trauma Team care. The BNP levels of all trauma patients will be drawn and the results statistically correlated with Head CT results and clinical course. The hypothesis is that BNP levels will rise significantly and proportionately to the severity of traumatic brain injury. It is unlikely that BNP levels will replace a head CT, but it may supplement head CTs or even replace serial head CTs with serial BNPs.